Earth and mars size comparison
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Mars and Earth Size Comparison: Diameter and Mass
Mars is significantly smaller than Earth. Mars has an average diameter of about 6,792 km, which is a little more than half of Earth’s diameter. This places Mars between Earth and the Moon in terms of size, making it the seventh smallest planet in the Solar System and the second smallest among the rocky planets, with only Mercury being smaller 134. In terms of mass, Mars is almost a tenth the mass of Earth and Venus, which is a notable difference explained by current planetary formation theories .
Surface Area and Gravity Differences
The surface area of Mars is about 144,798,500 km², which is roughly 28% of Earth’s total surface area. Interestingly, this is close to the total area of dry land on Earth, meaning if you combined all of Earth’s continents, it would be similar in size to the entire surface of Mars . Mars also has much lower surface gravity—about 37.6% that of Earth—meaning you would weigh much less on Mars than on Earth .
Atmospheric and Physical Characteristics
Mars’ atmosphere is much thinner than Earth’s, with a surface pressure of about 0.6 kPa compared to Earth’s 101 kPa. The Martian atmosphere is also mostly carbon dioxide (95%), while Earth’s is primarily nitrogen and oxygen . These differences in size and atmosphere contribute to the very different environments found on the two planets.
Astronomical Measurements and Observations
When observed from the same distance (the distance from the Earth to the Sun), Mars appears smaller in the sky than Earth. The angular diameter of Mars is about 11.1 arcseconds, while Earth’s is about 17.2 arcseconds, further highlighting the size difference between the two planets 23.
Planetary Formation and the Mars Size Mystery
Planetary formation models suggest that rocky planets should get larger the farther they are from the Sun, but Mars is an exception. While Venus and Earth are similar in size, Mars is much smaller than expected. Some recent models propose that Mars’ small size may be due to a partial gap in the solar nebula during its formation, which limited the material available for Mars to grow 35.
Conclusion
In summary, Mars is much smaller than Earth in both diameter and mass, with a surface area similar to Earth’s dry land and much lower gravity. Its thin, carbon dioxide-rich atmosphere and its unexpectedly small size compared to Earth are key differences that have intrigued scientists and shaped our understanding of planetary formation in the Solar System 1345.
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